Generac Power Systems NP-40G - Manual (Page 103)

Section 7.2- ENGINE DC CONTROL SYSTEM
Introduction
This Section contains troubleshooting informa­
tion pertaining to the engine DC control system.
The section is divided into two parts, I.e., trouble­
shooting flow charts and diagnostic test proce­
dures.
Use the flow charts and the test procedures In
conjunction with one another. The first step in
troubleshooting Is to identify the problem. After
Identifying the problem, go to the flow chart that
best describes it. Perform each test in the flow
chart and follow the flow chart arrows and Instruc­
tions. If you need instructions for any test, refer to
the applicable diagnostic test procedure.
Problem solving on the computer controlled gen­
erator Is somewhat more complex than problem
solving on conventional units, for the following
reasons:
□ The CCG circuit board, in addition to its voltage
and frequency control functions, has engine
shutdown capability. See AUTOMATIC SHUT­
DOWNS" on Page 1.2-5. The Engine Controller
board, part of the engine’s DC control system,
also has engine shutdown capability.
□ The CCG circuit board, in conjunction with the
Stepper Motor, controls engine throttle setting
as a means of voltage control. It may be diffi­
cult to differentiate between the computer or
DC control system as the cause of a problem.
Fortunately, neither the generator proper nor the
engine DC control system has a large number of
parts. When a problem is encountered, its solution
can usually be found after only a few tests.
Problem 1- Priming Function Does Not Work
REPAIR OR REPLACE
DEFECTIVE WIRE 14A
REPLACE SWITCH
IF DEFECTIVE
Page 7.2-1